imi trebuie URGENT !!!!

[tex]x + 1 \leqslant \sqrt{2} (x + 1)[/tex]
[tex]x + 1 \leqslant \sqrt{2} x + \sqrt{2} [/tex]
[tex]x - \sqrt{2}x \leqslant \sqrt{2} - 1[/tex]
[tex](1 - \sqrt{2} )x \leqslant \sqrt{2} - 1[/tex]
[tex]x \geqslant \frac{ \sqrt{2} - 1 }{1 - \sqrt{2} } [/tex]
[tex]x \geqslant \frac{ \sqrt{2} - 1 }{ - ( - 1 + \sqrt{2)} } [/tex]
[tex]x \geqslant - 1[/tex]
x €[-1,+infinit)
Explicație pas cu pas:
4.
√(3x-1)²+√(2y+3)²=0
|3x-1|+|2y+3|=0
|3x-1|=0
x=1/3
|2y+3|=0
y=-3/2
Deci: x=1/3; y=-3/2
6.
xy=25
x-y=2√5 (²)
(x-y)²=20
x²-2xy+y²=20
x²+y²=20+2xy
x²+y²=20+2*25
x²+y²=70
Bafta!